Two hundred schoolchildren in Britain, some as young as 13, have been identified as potential terrorists by a police scheme that aims to spot youngsters who are “vulnerable” to Islamic radicalisation.

The number was revealed to The Independent by Sir Norman Bettison, the chief constable of West Yorkshire Police and Britain’s most senior officer in charge of terror prevention.

He said the “Channel project” had intervened in the cases of at least 200 children who were thought to be at risk of extremism, since it began 18 months ago. The number has leapt from 10 children identified by June 2008.

The programme, run by the Association of Chief Police Officers, asks teachers, parents and other community figures to be vigilant for signs that may indicate an attraction to extreme views or susceptibility to being “groomed” by radicalisers. Sir Norman, whose force covers the area in which all four 7 July 2005 bombers grew up, said: “What will often manifest itself is what might be regarded as racism and the adoption of bad attitudes towards ‘the West’.

“One of the four bombers of 7 July was, on the face of it, a model student. He had never been in trouble with the police, was the son of a well-established family and was employed and integrated into society.

“But when we went back to his teachers they remarked on the things he used to write. In his exercise books he had written comments praising al-Qa’ida. That was not seen at the time as being substantive. Now we would hope that teachers might intervene, speak to the child’s family or perhaps the local imam who could then speak to the young man.”

The Channel project was originally piloted in Lancashire and the Metropolitan Police borough of Lambeth in 2007, but in February last year it was extended to West Yorkshire, the Midlands, Bedfordshire and South Wales. Due to its success there are now plans to roll it out to the rest of London, Thames Valley, South Yorkshire, Greater Manchester, Leicestershire, Nottinghamshire, and West Sussex.